摘要
Anodic urea oxidation reaction(UOR)is an intriguing half reaction that can replace oxygen evolution reaction(OER)and work together with hydrogen evolution reaction(HER)toward simultaneous hydrogen fuel generation and urea-rich wastewater purification;however,it remains a challenge to achieve overall urea electrolysis with high efficiency.Herein,we report a multifunctional electrocatalyst termed as Rh/Ni V-LDH,through integration of nickel-vanadium layered double hydroxide(LDH)with rhodium single-atom catalyst(SAC),to achieve this goal.The electrocatalyst delivers high HER mass activity of0.262 A mg^(-1) and exceptionally high turnover frequency(TOF)of 2.125 s^(-1) at an overpotential of100 m V.Moreover,exceptional activity toward urea oxidation is addressed,which requires a potential of 1.33 V to yield 10 mA cm^(-2),endorsing the potential to surmount the sluggish OER.The splendid catalytic activity is enabled by the synergy of the Ni V-LDH support and the atomically dispersed Rh sites(located on the Ni-V hollow sites)as evidenced both experimentally and theoretically.The selfsupported Rh/Ni V-LDH catalyst serving as the anode and cathode for overall urea electrolysis(1 mol L^(-1) KOH with 0.33 mol L^(-1) urea as electrolyte)only requires a small voltage of 1.47 V to deliver 100 mA cm^(-2) with excellent stability.This work provides important insights into multifunctional SAC design from the perspective of support sites toward overall electrolysis applications.
阳极尿素氧化反应(UOR)不仅可以取代析氧反应(OER)降低能耗,还可与析氢反应(HER)协同作用,同时产生氢燃料并净化富含尿素废水.然而,如何高效实现全电解尿素仍然面临挑战.本文首先将铑单原子催化剂(SAC)锚定到镍钒层状双氢氧化物(LDH)表面,以获得多功能电催化剂即Rh/NiV-LDH.该催化剂可以实现低能耗全电解尿素产氢目标.Rh/NiV-LDH在100 mV过电位下具有较高HER质量活性(0.262 A mg^(-1))和转化频率(TOF:2.125 s^(-1))此外,Rh/NiV-LDH表现出优异的UOR催化活性,仅需要1.33 V电压即可达到10 mA cm^(-2)的电流密度,表明UOR具备克服缓慢OER动力学缓慢的潜力.实验数据和理论计算证明,Rh/NiV-LDH出色的催化活性归因于NiV-LDH载体和单原子Rh位点的协同作用.将自支撑Rh/NiV-LDH分别作为尿素全电解池的阴极和阳极(1.0 mol L^(-1)KOH+0.33 mol L^(-1)尿素作为电解液),只需要1.47 V的低电压就可以提供100 mA cm^(-2)的电流密度且具有良好稳定性.这项工作从单原子精确调控的角度对全电解多功能SAC的设计具有重要指导意义.
作者
Huachuan Sun
Linfeng Li
Hsiao-Chien Chen
Delong Duan
Muhammad Humayun
Yang Qiu
Xia Zhang
Xiang Ao
Ying Wu
Yuanjie Pang
Kaifu Huo
Chundong Wang
Yujie Xiong
孙华传;李林峰;陈効谦;段德龙;穆汗默德胡马运;邱杨;张霞;敖翔;吴瑛;庞元杰;霍开富;王春栋;熊宇杰(School of Optical and Electronic Information,Wuhan National Laboratory for Optoelectronics,Optics Valley Laboratory,Huazhong University of Science and Technology,Wuhan 430074,China;Center for Reliability Science and Technologies,Chang Gung University,Taoyuan 33302,China;Kidney Research Center,Department of Nephrology,Chang Gung Memorial Hospital,Linkou,Taoyuan 33305,China;School of Chemistry and Materials Science,University of Science and Technology of China,Hefei 230026,China;Pico Center,SUSTech Core Research Facilities,Southern University of Science and Technology,Shenzhen 518055,China;College of Chemistry and Chemical Engineering,Tarim University,Alaer 843300,China)
基金
finically supported by the National Key R&D Program of China(2017YFE0120500)
the National Natural Science Foundation of China(51972129,51702150,and 21725102)
the Key Research and Development Program of Hubei(2020BAB079)
Bintuan Science and Technology Program(2020DB002,and 2022DB009)
the Science and Technology Innovation Committee Foundation of Shenzhen(JCYJ20210324141613032 and JCYJ20190809142019365)。
